63,652 research outputs found
Sitagliptin attenuates cardiomyopathy by modulating the JAK/STAT signaling pathway in experimental diabetic rats
No full textNouf M Al-Rasheed,1 Nawal M Al-Rasheed,1,2 Iman H Hasan,1 Maha A Al-Amin,1 Hanaa N Al-Ajmi,1 Ayman M Mahmoud3 1Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, 2Department of Pharmaceutical Sciences, College of Pharmacy, Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia; 3Physiology Division, Department of Zoology, Faculty of Science, Beni-Suef University, Beni-Suef, Egypt Abstract: Sitagliptin, a dipeptidyl peptidase-4 inhibitor, has been reported to promote cardioprotection in diabetic hearts by limiting hyperglycemia and hyperlipidemia. However, little is known about the involvement of the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway modulation in the cardioprotective effects of sitagliptin. The current study aimed to investigate the protective effects of sitagliptin against diabetic cardiomyopathy (DCM), focusing on the modulation of the JAK/STAT pathway. Diabetes was induced by streptozotocin injection, and rats received sitagliptin orally and daily for 90 days. Diabetic rats exhibited hyperglycemia, hyperlipidemia, and a significant increase in heart-to-body weight (HW/BW) ratio. Serum troponin I and creatine kinase MB, cardiac interleukin-6 (IL-6), lipid peroxidation, and nitric oxide levels showed significant increase in diabetic rats. In contrast, both enzymatic and nonenzymatic antioxidant defenses were significantly declined in the heart of diabetic rats. Histopathological study revealed degenerations, increased collagen deposition in the heart of diabetic rats. Sitagliptin alleviated hyperglycemia, hyperlipidemia, HW/BW ratio, histological architecture, oxidative stress, and inflammation, and rejuvenated the antioxidant defenses. In addition, cardiac levels of pJAK2 and pSTAT3 were increased in diabetic rats, an effect which was remarkably decreased after sitagliptin treatment. In conclusion, these results confer an evidence that sitagliptin has great therapeutic potential on DCM through down-regulation of the JAK/STAT signaling pathway. Keywords: diabetic cardiomyopathy, DPP-4 inhibitors, JAK/STAT, oxidative stress, inflammatio
Calendar conversion for real-time systems
No full textIn some applications of real-time systems such as monitoring and control, calendar referencing plays a significant role. The system needs the precise year, month, day, hour, minute and second in order to function correctly. Generally, real-time systems are based on computers whose operating systems use the Gregorian calendar. The official calendar of some countries, however, is not based on the Gregorian calendar. To reduce the human errors and make the system friendlier, it is necessary to present the date in the local format. In this paper, the optimum method of time-keeping for a distributed real-time system is described and then a solar calendar called Khayyami is reviewed and a novel algorithm for conversion between Gregorian and Khayyami calendars is presented. Khayyami is the official calendar of Iran and Afghanistan and is used in surrounding areas such as the Central Asian countries and Kurdish area. The methods described in this paper were implemented in a monitoring and control system and the practical results justify these
A Fast and Accurate Process Variation-aware Modeling Technique for Resistive Bridge Defects
No full textRecent research has shown that tests generated without taking process variation into account may lead to loss of test quality. At present there is no efficient device-level modeling technique that models the effect of process variation on resistive bridge defects. This paper presents a fast and accurate technique to achieve this, including modeling the effect of voltage and temperature variation using BSIM4 transistor model. To speedup the computation time and without compromising simulation accuracy (achieved through BSIM4) two efficient voltage approximation algorithms are proposed for calculating logic threshold of driven gates and voltages on bridged lines of a fault-site to calculate bridge critical resistance. Experiments are conducted on a 65-nm gate library (for illustration purposes), and results show that on average the proposed modeling technique is more than 53 times faster and in the worst case, error in bridge critical resistance is 2.64% when compared with HSPICE
Generation of an ultrastable 578 nm laser for Yb lattice clock
No full textIn this paper we described the development and the characterization of a 578 nm laser source to be the clock laser for an Ytterbium Lattice Optical clock. Two independent laser sources have been realized and the characterization of the stability with a beat note technique is presente
Simvastatin prevents isoproterenol-induced cardiac hypertrophy through modulation of the JAK/STAT pathway
No full textNouf M Al-Rasheed,1 Maha M Al-Oteibi,1 Reem Z Al-Manee,1 Sarah A Al-Shareef,1 Nawal M Al-Rasheed,1 Iman H Hasan,1 Raeesa A Mohamad,2 Ayman M Mahmoud3 1Department of Pharmacology, Faculty of Pharmacy, 2Department of Anatomy, College of Medicine, King Saud University, Riyadh, Saudi Arabia; 3Physiology Division, Department of Zoology, Faculty of Science, Beni-Suef University, Egypt Abstract: Simvastatin (SIM) is a lipid-soluble inhibitor of hydroxy-3-methylglutaryl coenzyme A reductase with multiple reported therapeutic benefits. The present study was designed to investigate the effect of pretreatment with SIM on isoproterenol (ISO)-induced cardiac hypertrophy in rats. Twenty-four male albino Wistar rats weighing 180–200 g were divided into four groups. Groups I and III received normal saline while groups II and IV received SIM (10 mg/kg body weight) for 30 days per gavage. In the last 7 days, rats of groups III and IV were administered ISO (5 mg/kg) intraperitoneally to induce cardiac hypertrophy. Administration of ISO induced an increase in heart-to-body weight (HW/BW) ratio, an increase in serum interleukin-6, and elevated systolic and diastolic blood pressure. Serum levels of lipids, cardiovascular risk indices, and cardiac troponin I and creatine phosphokinase-MB showed significant increase in ISO-induced hypertrophic rats. Histopathological examination of heart tissue revealed focal areas of subendocardium degeneration, mononuclear cellular infiltrations, fibrous tissue deposition, and increased thickness of the myocardium of left ventricle. In addition, ISO-administered rats exhibited significant upregulation of cardiac Janus kinase, phosphorylated signal transducer and activator of transcription, and nuclear factor-kappa B. Pretreatment with SIM significantly prevented ISO-induced cardiac hypertrophy, alleviated the altered biochemical parameters, and improved the heart architecture. In conclusion, our study provides evidence that SIM prevented the development of cardiac hypertrophy via modulation of the Janus kinase/signal transducer and activator of transcription-signaling pathway in the heart of ISO-administered animals. Keywords: simvastatin, cardiac hypertrophy, JAK/STAT pathway, IL-6, isoprotereno
The Influence Of Equal Channel Angular Pressing Angles On The Microstructure And Properties Of Al-Si-Mg Alloy [TA483. J91 2006 f rb].
No full textPenyelidikan ini bertujuan untuk meningkatkan sifat-sifat fizikal dan mekanikal aloi Al-Si-Mg melalui penghalusan struktur ira yang dihasilkan oleh kecacatan plastik lampau.
The aim of this research is to improve the physical and mechanical properties of Al-Si-Mg alloy by grain structure refinement produced by severe plastic deformation through equal channel angular pressing (ECAP)
Een introductie op de verkeersstroomtheorie
No full textMet ingang van deze uitgave zal NM Magazine een aantal tutorials over (dynamisch) verkeersmanagement opnemen. Ons doel? Een groter publiek kennis laten maken met de principes van en de wetenschappelijke basis onder verkeersmanagement. In deze eerste bijdrage maken we kennis met de verkeersstroomtheorie. Dr. Victor Knoop en dr. ir. Andreas Hegyi van TU Delft praten ons bij over microscopische en macroscopische vergelijkingen, het fundamenteel diagram en de capaciteitsval.Transport and PlanningCivil Engineering and Geoscience
On the fragmentation of furan molecule and its dependence on the laser wavelength
No full textThe fragmentation processes of the aromatic conjugated diene systems have been studied by many research groups [1–10]. Derrick et al. [1], have studied the electronic structure using photoelectron spectroscopy, where a number of highly excited Rydberg states were accessed, also they attributed the fragmentation of the furan molecule to the photoelectron energy responsible for the breaking of the C–C bond or the C–O bond. Rockwood et al. [10], using a fixed frequency KrF laser (249 nm), and Zandee and Bernstein [4], using nitrogen laser pumped dye laser, both found extensive ion fragmentation as the laser power density was increased. Cooper et al. [5] studied the fragmentation process of the benzene, pyrrole, and furan molecules using the resonantly enhanced multiphoton ionization technique; they stated that the fragmentation process for benzene was efficient at the highest laser power density 5 × 109 W/cm2, for furan molecule at a laser wavelength of 376 nm, in a two–photon resonance the parent ion was seen as the strongest peak, while at 550.5 nm in a three–photon resonance the parent ion was not seen in full laser power, and only appeared slightly at 54% of the laser power. Boesl et al. [6], in a work done on the fragmentation of furan, reported a weak dependence of the ion efficiency on wavelength
De kennisagenda als gids voor de Routekaart
No full textOp dinsdag 20 mei organiseerden NM Magazine en Stichting PAO in samenwerking met Connecting Mobility een werksessie over de Routekaart van het actieprogramma Connecting Mobility. De sessie had tot doel de belangrijkste kennisvragen op het gebied van onder meer verkeerskunde, regeltechniek, human factors, ict en businessmodellen te identificeren. Hiermee is een eerste stap gezet naar een breed gedragen kennisagenda.Transport & PlanningCivil Engineering and Geoscience
Modeling the Impact of Process Variation on Resistive Bridge Defects
No full textRecent research has shown that tests generated without taking process variation into account may lead to loss of test quality. At present there is no efficient device-level modeling technique that models the effect of process variation on resistive bridges. This paper presents a fast and accurate technique to model the effect of process variation on resistive bridge defects. The proposed model is implemented in two stages: firstly, it employs an accurate transistor model (BSIM4) to calculate the critical resistance of a bridge; secondly, the effect of process variation is incorporated in this model by using three transistor parameters: gate length (L), threshold voltage (V) and effective mobility (ueff) where each follow Gaussian distribution. Experiments are conducted on a 65-nm gate library (for illustration purposes), and results show that on average the proposed modeling technique is more than 7 times faster and in the worst case, error in bridge critical resistance is 0.8% when compared with HSPICE
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